(STB-44) table
Standard deviations are now reported correctly when aweights are
specified.

(STB-44) xtglsxtgls, when computing AR(1) correlations by panel for a large
number of panels, did not place all the correlations in the saved result
S_E_rho. There were no errors in reported results.

(STB-44) xtregxtreg, fe now uses better logic for dropping of
constant-within-panel variables. Previously, a constant variable might
not be dropped and then results looked odd (but were correct).

(STB-43) heckmanheckman now has the capability to estimate models with variables
that perfectly predict selection. Previously heckman would simply
drop such variables from the selection equation, which is inappropriate
in most cases.

(STB-43) kapkap has been modified to deal with a large number ratings.
Previously, it would issue the error message "too many ratings".

(STB-43) kdensitykdensity now works correctly with aweights.

(STB-43) stackdescribe, run after stack, no longer shows that the data is
saved under a temporary filename.

(STB-43) sts
The new atrisk for use with sts graph shows the number of
subjects at risk at the beginning of each interval; see help sts.

stata52. (STB-42) stssts graph now plots survival curves, etc., from time t=0 rather
than from the first observed time of failure or censoring. The new
noorigin option restores the original behavior.

(STB-42) bstrap, bsample
These commands did not work with the idcluster() option; they now
do.

(STB-42) kap
One of the new syntax features introduced for kap in STB-41
— the ability to specify more than two variables — did not
work; doing that returned a syntax error. All new features work now.

(STB-41) fracpoly, fracplot, fracgenfracplot now produces a component+residual plot for Cox regression
using martingale residuals. Previously, no residuals were used. (You
can recover the old type of plot by using the undocumented nopts
option.) In addition, the following changes to the output have been
made:

P-values from F-tests presented when option compare is specified
have been corrected: previously they did not correctly account for
the degrees of freedom associated with estimation of the FP powers.
The change is very slight in most cases.

The compare table has been reformatted slightly: a column for df
has been added and the column previously labelled P is now labelled
P(term).

fracgen reports creation of new variable(s) followed by the phrase
"if _sample", stressing the use of an estimation sample.

(STB-41) lincom
The new hr option allows the output to be labeled as Hazard
Ratios, which is useful when lincom is used after survival
estimators.

stata51 (STB-41) mcc, mccimcc and mcci now report the exact McNemar test in addition
to what was previously reported. There is no change in command syntax.
(Programmers: the new significance value is stored in the global macro
$S_24.)

(STB-41) ologitp, oprobitp
These commands now work after the svyolog and svyoprob
commands introduced in STB-40.

sdtest and sdtesti previously reported incorrect one-sided
p-values — the degrees of freedom where interchanged — the
two-sided p-value was corrrect. This is fixed. In addition,
sdtest and sdtesti now display standard deviations and
string variables are allowed with by().

svy6 (STB-40) svymlog, svyolog, svyoprob
Three new commands, equivalent to mlogit, ologit, and
oprobit, are introduced for estimating multinomial logistic and
ordered logit and probit models using complex survey data.

(STB-40) stack
The new group() option provides an easier way to use stack.
In addition, stack's into() option now understands variable
ranges.

(STB-40) stereg, ereg
If score(newvar) was specified and the model was estimated
in the log-time metric, stereg and ereg created newvar with
the sign reversed. This is fixed.

(STB-40) sureg
Previously degrees of freedom were calculated as
N-round(mean(k1,k2,...))*e, where N is the number of observations, k1,
the number of estimated parameters less the intercept in the first
equation, k2 the same thing for the second equation, etc., and e the
number of equations. This has been changed to N-round(mean(k1,k2,...)).

(Stata website) xtgee, xtpois, xtprobit
Estimation of the exchangeable working correlation parameter was
incorrect in the presence of singletons — groups containing single
observations. In the presence of singletons, the estimated working
correlation was attenuated; if the proportion of singletons was small,
the effect was negligible. (This same bug affected S-plus and SAS's PROC
GENMOD.)

In addition, these commands are updated to change the calculation of the
scale parameter. Formerly, N was used as the divisor; now N-k is used.
Either will work in that any consistent estimate of phi is adequate, but
most other implementations use N-k.

There are two parts to this update: the updated xtgee.ado ado-file and
an updated executable. Your Stata executable needs to be dated at least
14 Oct 1997 (type query born to the Stata prompt). If it is older
than that, obtain the latest executable.

(STB-39) bs
Very long (over 600 character) bs commands could result in an
"invalid syntax" error. The problem is now fixed.

(STB-39) kapkap now displays tables with missing rows/columns more prettily.

(STB-39) reshape
All new syntax is introduced; the new reshape command continues to
understand the old syntax.

(STB-39) swsw now may be used with nbreg.

(STB-38) stbasestbase without the at() option produced incorrect results
when either the data had gaps or there were multiple failures per
subject. In such cases, stbase lost the observation on the first
failure of each subject. stbase produced correct results when the
data did not have gaps and there were no multiple failures per subject.

(STB-38) ttest, ttestittest and ttesti now produce answers when one of the groups
has only one observation.

(STB-37) aregareg refused to produce estimates of the constant-only model when
no regressors were specified.

(STB-37) sts
The t2title() option did not work; sts graph ignored it.

(STB-37) svyratiosvyratio with the by() option did not label the output
clearly.

(STB-37) xtgee
The noconstant option did not work; xtgee refused to
estimate the model.

(STB-36) bs
Previously, bs was supposed to have a cluster() option but
did not. It now does.

(STB-36) cscs with the by() option produced incorrect Mantel-Haenzel
combined risk ratio when one or more of the strata had infinite risk
ratios (no cases in the strata). To produce the incorrect result, (1)
you had to specify the by() option, (2) you must not have
specified the or or rd options (which would cause cs
to report something other othan risk ratios), and (3) there must have
been one or more strata with infinite risk ratios (risk ratio reported as
missing in the output). The incorrectly calculated result is now fixed.

(STB-36) dotplot
Previously, the meanmedian and nogroup options did
not work: if you specified them, you got a syntax error. They now work.
In addition, new options vertbounded and incr()
have been added.

(STB-36) lincomlincom now allows longer expressions.

(STB-36) merge
There was no problem. The on-line help file, however, incorrectly said
that the nokeep option omitted observations that would have been
marked _merge==1 when it should have said that it omitted
observations that would have been marked _merge==2

(STB-36) matrix
There was no problem. The on-line help file, however, provided an
incorrect syntax diagram for matrix accum

(STB-36) prtestprtesti
These commands now report the standard error under the null hypothesis in
addition to the statistics previously reported.

(STB-36) stssts graph with the adjustfor() option could produce titles
for graphs that were so long that Stata would then refuse to draw the
graph.

(STB-36) swsw may now be used with clogit

(STB-36) ttestttestittest and ttesti now include a level() option to
specify the level for the confidence interval.

(STB-36) xtgee
The criteria for detecting divergence of the model was updated.

(STB-35) bitest, bitesti
For certain extreme values of the test statistic, bitest and
bitesti would report a two-sided p-value of 1 rather than 0.

crc46 (STB-35) dydx, integ
These commands have been improved and now fit a cubic spline to the data
and use that to produce the derivative and integral.

(STB-35) joinby
Under rare circumstances joinby would produce a dataset with no
observations when it should have produced something else. Note that if
the old joinby produced a dataset that had any observations, it
was correct.

(STB-35) loneway
When there were weights and missing values of the outcome or group
variables, loneway did not produce the correct ANOVA table. This
is fixed. In addition, you are warned that there may still be
outstanding issues with this command concerning the reliability statistic
and the intraclass correlation coefficient; see Gleason (1997), sg65:
Computing intraclass correlations and large ANOVAs, STB-35.

(STB-35) stir
The note at the top that reports which values corresponded to the exposed
and unexposed categories was backwards. Statistics were correct.

crc45 (STB-35) stset
Two new options have been added to stsetfirst and
forcefirst specifies that events after the first failure
event in time-varying data are to be ignored. force drops
obsrvations with missing values of the time, outcome, id()t0() or weighting variables. See help stset.

(STB-35) swsw leaves behind variable _sample for use by other
programs. This variable indicates which observations were used in
producing results. _sample was incorrectly not set to 0 for
observations containing missing values of the dependent variable even
though such observations were not used. Note that the stepwise results
reported were correct.

In addition, two more changes were made: sw regress now allows
the beta option. sw logistic now allows the robust
and cluster() options.

(STB-35) xtgee, xtprobit, xtpois
Three changes are made. First, the divergence criterion for probit and
logit models is relaxed, making the "estimates diverging" error message
less likely. Second, the noconstant option may now be spelled out
as the manaul indicates. Before the change, it had to be abbreviated.
Third, the time variable t() is now required in the case of
corr(fixed)

bsample, bstrap, bs
Due to an error in bsample, the cluster() option on all
three of these commands did not give a proper bootstrap sample.

(STB-34) prtest, sdtest, ttest
These commands produced obviously incorrect output when the grouping
These commands produced obviously incorrect output when the grouping
variable was labeled and the label contained blanks.

In addition, confidence intervals were labeled 95% even when other than
95% was requested (the requested confidence interval was, however,
shown).

sts graphsts graph with the lost option produced incorrect
Kaplan-Meier plots (without the lost option results were correct).

In addition, sts graph has been modified to display the
Kaplan-Meier curve out to the last censoring or death. Previously, the
curve was displayed out to the last death only.

(STB-34) swsw refused to allow pweights or iweights.

(STB-34) xtgee, xtprobit When faced with certain inestimable
models, xtgee and xtprobit would report "conformability
error". The error message is improved. In addition, the checks for
diverging models were improved.

In addition, sts graph has
been modified to display the Kaplan-Meier curve out to the last censoring
or death. Previously, the curve was displayed out to the last death
only.